The present invention relates to an exposure technique for exposing an object with a plurality of optical elements capable of spatially transforming light (spatially modulating light) and to a device manufacturing technique using such exposure technique.
In a lithography process for manufacturing devices (electronic devices and micro-devices), such as semiconductor devices and liquid crystal display devices, an exposure apparatus such as a batch exposure type projection exposure apparatus, like a stepper, or a scanning exposure type projection exposure apparatus, like a scanning stepper, is used to transfer a predetermined pattern onto a wafer (or glass plate etc.).
In an exposure apparatus of the prior art, to form different circuit patterns in a plurality of layers on a device that is subject to processing, masks are exchanged for each layer to perform exposure. Further, when a circuit pattern for a single layer includes, for example, two types of circuits patterns having different microscopic levels, mask patterns for the two types of circuit patterns are formed on two different masks. The patterns of the two masks are sequentially exposed in a superimposed manner onto a wafer while optimizing illumination conditions to perform double exposure. In this manner, when exchanging masks for each device, each layer, or each pattern type, throughput is decreased in the exposure process.
Therefore, an exposure apparatus has been proposed to use, in lieu of masks, two mirror devices including an array of a plurality of movable micro-mirrors and control the direction of reflection light for each micro-mirror of the two mirror devices in order to produce light intensity distribution in correspondence with a transfer pattern (for example, refer to Japanese Laid-Open Patent Publication No. 2006-13518). In this exposure apparatus, the two mirror devices are illuminated with linear polarized lights of which polarization directions are orthogonal to each other. Two types of patterns are simultaneously exposed by synthesizing light beams from the two mirror devices and generating illumination light that exposes a wafer.